Graphics workshop designbyIZO has taken a good hard look at the typefaces used in some of the most popular operating systems. Windows 7's Segoe UI, OS X's Lucida Grande, iOS's Helvetica Neue, Android's Droid Sans, and the eponymous Ubuntu are all sized up (though there's no mention of Roboto, the new font for Android 4.0). Each are key to how we interact with our computers and devices and each has subtle differences that affect readability. Ultimately, this can affect the speed which we use our gadgets at, even if that's only by a few milliseconds.
And the result? Using a variety of comparisons, the author Ian Hex concludes that Droid Sans is consistently the best of the bunch — he points out that it's designed specifically for smaller screens so should fare well when scaled down. He doesn't stop there, though: he also gives some suggestions for other fonts to try if you feel like something new. Follow the source link for a full look at his reasoning.